Burglar-alarm



No.-6|l,772. Patented Oct. 4, |898, S. CUFFIELD.

BURGLAR ALARM.

(Application tile Dec. 31,

oooooooo f MM l f X M I IM Mind@ MMMMMMMMMMMMMMMM UNITED STATES PATENT OEEICE.

SAMUEL COFFIELD, OF VINAMAC, INDIANA.

`BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 611,772, dated October 4, 1898. Application filed December 31,1897. Serial No. 664,991. (No model.)

To LLZZ whom it may concern.-

Be it known that I, SAMUEL CoEE1ELD,.re siding at Winamac, in the county of Pulaski and State of Indiana, have invented a new and useful Door-Alarm, of which the following is a specification. n

This invention relates to improvements in door-alarms; and the object thereof is to provide a device which may be att-ached to the door-knobs, so that as the same are turned from either side of the door to open the latter the alarm-bell will ring, thus giving notice that some one has turned the knobs and entered or attempted to enter the house or room.

With the above object in view the invention consists in the improved construction, arrangement, and combination of parts hereinafter fully described,and afterward specifically pointed out in the claims.

In order to enable others skilled in the art to which my invention most nearly appertains to make and use the same, I will now proceed to describe its construction and operation, having reference to the accompanying drawings, forming part of this specification, .in which- Figure l is a perspective view of my invention applied to a door. Fig. 2 is a vertical sectional View throughl the door-knob and spindle, the gong being removed from its attaching-plate. Fig. 3 is a top plan View.

Like letters of reference mark the same parts wherever they occur in the various figures of the drawings.

A Referring to the accompanying drawings, A indicates a gong, of any desired construction, having the thumb-piece B thereof, which operates .the striker, provided with the aperture C.

D is an arm which is screw-threaded,whereby it is attached to the spindle E of the doorknobs, said arm passing through the inner knob and securing the same to the spindle. The outer end of this arm is provided with an aperture F to receive the hooked end G of the pull-rod I-I, the opposite end of this pullrod being screw threaded and movable through the aperture of the thumb-piece B of the gong. A sleeve I is adjustable upon the screw-threaded end of the pull-rod, and has the head .I on its outer end, which head is slotted, as illustrated at K, whereby it may be adjusted by means of a screw-driver. A spring L is coiled about the sleeve between the head thereof and the thumb-piece I-I. By means of this adjustable sleeve the rotation of the knobs necessary to ring the gong is regulated as may be desired.

From the'above description it will be seen that as the door-knob is turned from either side Yof the door the gong is sounded through the medium of the pull-rod and notice given of the entrance or attempted entrance of any one into the house or room.

While I have illustrated and described the best means now known to me for carrying out my invention, I do not wish to be understood as restricting myself to the exact details of construction shown and described, but hold that any slight changes or variations such as might suggest themselves to the ordinary mechanic will properly fall 'within the limit and scope of my invention.

.Having thus fully described myinvention, what I claim as new, and desire to secure by Letters Patent of the United States, s-

1. The combination with a door-knob having a transversely-extending arm, of a gong having an apertured thumb-piece, a pull-rod pivoted at one end to the arm and movable at its opposite end through the aperture of the thumb-piece, a spring carried by said pull-rod adjacent its" outer end and bearing against the outer face of the thumb-piece,

and means for Varying the tension of saidI spring, substantially as set forth.

2. The combination with a door-knob having a transversely-extending arm, of a gong having an aperturedthumb-piece, a pull-rod pivoted at its inner end to the transverselyextending arm and screw-threaded at its opposite end, a sleeve adjustable on said screwthreaded end ,and movable through the apertured thumb-piece, anda s'pring.carried by said sleeve and engaging the outer face of the thumb-piece, substantially as set forth.

SAMUEL COFFIELD.

I'Vitnesses: v

CARLTON SMITH, CHARLES W. SWISHER. 

